The present invention relates to a high pressure seal assembly utilized to seal relatively movable parts against each other to prevent leakage of fluid therebetween. More particularly, the invention relates to a high pressure seal assembly for axially displaceable and/or rotatable pistons, piston rods, shafts or the like, by means of at least one seal or guide ring formed of a material which is elastically or plastically deformable under pressure, and a supporting ring positioned on said guide ring.
Known high pressure seal assemblies include a rigidly mounted supporting ring of a material which is practically non-deformable under operational conditions, which supporting ring supports and lodges a seal made of a material which is elastically or plastically deformable under pressure. Such materials can be elastomers, PTFE-impregnated plastic or mineral fiber fabrics and/or compounds or similar block-type packings in the form of grooved rings, squared cords, striplike rings, etc. A guide ring provided together with the seal or in place of the seal and made of material deformable under pressure has served the purpose of supporting the seal and/or guiding the plunger piston, piston rod, piston or shaft or the like and had to be also supported an lodged. The supporting ring therefore is rididly mounted at the low pressure side of the seal. An annular play or gap is formed between the relatively movable parts. If this play were selected so great that the lateral contact of these parts relative to each other and a resulting damaging of sliding surfaces would be avoided, then the deformable seal or guide ring would be extruded under operating pressure into the annular play and the seal under operating condition would be sooner or later damaged. If, on the other hand, the annular play were so small so that the extrusion of the deformable seal or guide ring into the annular play would not be possible the parts would tend to contact each other due to unavoidable radial deflections, which would lead to damaging of sliding surfaces.